What causes acoustic problems? Measures to prevent them
- 14 hours ago
- 13 min read
During live streaming or corporate events where audio problems occur, speakers' voices and important information cannot reach viewers, and the content cannot be conveyed as intended.
While advances in equipment and distribution technology have made it easier to hold online seminars and hybrid events, they have also made it easier for problems such as audio dropouts and noise to occur.
This article will explain the causes of acoustic problems and how to deal with them.
At LIFE.14, we design all the equipment needed for video, audio, streaming, filming, and simultaneous interpretation, including solutions to audio problems during live streaming and corporate events.
We have been involved in technical design and on-site operations to prevent audio problems, including microphone configuration, mixer settings, backup recording, and securing safety tracks.
Even if you don't want to have any acoustic problems or have had problems in the past, we can propose specific measures from the planning stage. Please feel free to contact us for a consultation.
Common acoustic problems on site
The following are some typical examples of common acoustic problems that occur on-site:
No sound
The sound is distorted
howling
noise
Audio delay
Here we will take a closer look at each symptom and how to deal with it.
No sound
The main reasons for no sound are that the power is not turned on, the device is muted, or incorrect wiring.
As a countermeasure, check the power supply, cable connections, and channel settings in order, and check that the output destination of your mixer and streaming software is correct.
With wireless devices, interference or dead batteries can be a problem, so it's important to have spare batteries and adjust the antenna position.
The sound is distorted
If the input level is too high, the sound will distort, and if it is too low, noise will be noticeable.
The main causes are microphone or mixer gain settings, or excessive speaker output.
Generally, you adjust the channel input level meter so that it peaks in the appropriate range (roughly around 0 dB), and balance it so that the master output isn't excessive.
Be sure to control the output level so that it does not exceed the allowable level of the speakers or amplifier to which it is output.
Do not turn up the volume on your headphones more than necessary, and be careful not to strain your hearing when monitoring for long periods of time.
On the other hand, if the input is too weak, surrounding noise will become relatively more noticeable, so it is important to ensure an appropriate input level and maintain the S/N ratio (signal-to-noise ratio).
howling
Feedback occurs when the microphone and speaker are placed too close together or when certain frequencies are emphasized.
Howling is caused by a feedback loop in which the sound from the speaker is returned to the microphone and amplified, and is caused by a problem with the equipment, settings, or environment. The main countermeasures are as follows:
Reduce the number of microphones and increase the distance between the microphones and the speakers
Do not point the microphone towards the speaker
Keeping input levels appropriate
If there is excessive reverberation, adjust it using sound-absorbing materials or an equalizer.
When using multiple wireless microphones, use the channel plan recommended by the manufacturer to avoid frequency interference, and install the antennas in a visible location to ensure reception sensitivity.
noise
Possible causes of noise include power supply noise, poor earthing, and poor cable contact.
The longer the cable, the more susceptible it is to external electromagnetic noise, so using a balanced connection or shielded cable is effective.
Also, since noise and malfunctions can occur due to aging electronic devices and metal fatigue, it is important to perform regular maintenance and inspect cables.
When connecting other devices to the same power supply circuit, a humming noise is likely to occur, so it is necessary to separate the power supply systems and check the earthing.
Audio delay
When streaming video, there can be a "audio delay" where only the audio is heard late.
The main causes are unstable communication lines and insufficient processing power of the distribution software and devices being used.
Effective solutions include using a wired LAN connection, closing unnecessary apps and browsers, and lowering the video and audio quality appropriately.
A wired connection is more stable than Wi-Fi and reduces latency.
Video distribution software also has settings for synchronizing audio and video, and you can also use the delay compensation function (audio delay function) to synchronize them.
Acoustic problems can have a major impact on the success of an event.
Acoustic problems can affect the success of your event in a number of ways:
This leads to distrust of the content of the announcement itself.
Speakers' ratings go down
Leading to viewers (potential customers) abandoning
Information spreads on social media
Lower evaluation from business partners
Let's take a look at how acoustic problems can actually affect the event itself.
This leads to distrust of the content of the announcement itself.
If the audio is distorted during an earnings briefing or product announcement, it could raise doubts about the company's management structure before even considering the content.
Investors and the media place importance on the accuracy and transparency of information, and if they are unable to fully understand the materials due to audio interruptions, this can lead to suspicions that information is being concealed.
This distrust has a direct impact on a company's stock price and brand value.
It is important to eliminate acoustic problems before they occur through careful preparation and a backup system.
Speakers' ratings go down
If the audio is unclear, the speaker's content will not be conveyed, and their expertise and persuasiveness will not be properly evaluated.
No matter how good a speaker or executive's presentation is, if the audience cannot hear it, the impression will be weaker and the presentation may be poorly received.
Even if it's not the speaker's fault, a negative impression can still be left as a result of the event organizers failing to provide an appropriate acoustic environment.
Leading to viewers (potential customers) abandoning
If the audio is distorted during a broadcast, viewers are more likely to drop out, leading to lower re-watch rates.
Especially in online seminars, where customers can easily switch to competitors' content, poor sound quality can result in lost opportunities.
To prevent dropouts, it is essential to verify voice quality in advance and, if a problem occurs, quickly identify the cause and restore service.
Information spreads on social media
Nowadays, events are instantly shared on social media, and any problems are spread to many users.
If the broadcast is interrupted or feedback continues, comments such as "It's unbearable to listen to" or "It's unprofessional" will spread quickly and appear in search results.
Such bad publicity can affect future business negotiations and recruitment activities, so venues should make efforts to restore credibility by responding quickly and reporting after the fact.
Lower evaluation from business partners
Even for companies with which we have long-term business relationships, a single serious acoustic incident can affect our decision to renew the contract.
In particular, any deficiencies at IR events or shareholders' meetings could affect the reliability of financial information for business partners, and could have an impact on future projects.
In order to ensure operational quality, it is important to not only consider the technical aspects but also to prepare management systems and contractual details, and to present countermeasures in case of an emergency.
Causes of acoustic problems
The reasons why sound may be distorted at a venue or streaming site are as follows:
Equipment failure
Volume setting error
Signal design error
Influence of the surrounding environment
The management's lack of thoroughness
Let's take a closer look at the problems that each of these factors can cause.
Equipment failure
Physical issues such as a broken microphone or cable, loose contacts, or a dead battery cannot be fixed by restarting the device and require replacement or rewiring.
Therefore, before each day's operation, check the cables and power supply visually and by turning them on, and check that the microphones and recording/playback equipment are working properly.
Electronic devices are prone to component deterioration and loose contacts over long-term use, so it is a good idea to have them regularly maintained and inspected by a professional every six months to one year.
Volume setting error
If the microphone input is too strong, distortion will occur, and if it is too weak, noise will be noticeable.
Generally, adjust the GAIN or TRIM knob so that the input level meter for each channel peaks in the appropriate range (roughly around 0 dB), and balance the master output so that it doesn't become excessive.
Setting the volume above the allowable level of the output speakers or amplifier can lead to distortion or equipment damage, so it is important to adjust the overall volume while checking it in stages.
When connecting multiple devices, be careful not to double the gain at each stage.
Signal design error
If the design of which device the sound flows from to which device is unclear, problems such as no sound, double sound, or delays will occur.
When preparing for an event, arrange microphones and speakers according to a line chart or system diagram, check the signal input and output, and make sure sound is coming from each speaker.
Without proper blueprints and sharing between engineers, wiring errors and confusing signal paths are likely to occur.
When handling venue sound and streaming audio at the same time, it is important to organize the systems.
Influence of the surrounding environment
The surrounding environment, including air conditioning noise, external noise, reverberant walls, and metal fixtures, can also cause acoustic problems.
If a microphone and speaker are used in the same space, the sound from the speaker may re-enter the microphone and be amplified repeatedly, resulting in feedback.
Additionally, certain frequencies can be reflected depending on the materials of the walls and ceiling, causing the sound to sound muffled or high-pitched.
Install sound-absorbing panels or curtains as needed to adjust the reverberation characteristics of the venue.
When streaming online, unstable communication lines can also cause audio dropouts and delays.
To ensure stable audio, it is effective to appropriately lower the video and audio quality or switch to a wired LAN.
The management's lack of thoroughness
Lack of preparation in terms of operations, such as insufficient rehearsal, unclear division of roles, and absence of a supervisor, will delay response when problems arise.
When rehearsing for the actual event, select the type and number of microphones to suit the movements of the speakers and MC, and even check their positions and the timing for changing the background music.
By performing audio checks while recreating actual traffic flow, unexpected problems can be prevented.
Assigning each person in charge, such as a stage director, sound and lighting staff, and clearly defining their roles will lead to smooth operation and ensure safety.
Measures to prevent acoustic problems
Many acoustic problems can be prevented with advance preparation and checking.
The main measures are as follows:
Unification of volume standards
Sharing signal path diagrams
rehearsal
Establishment of a monitoring system
Separate design for venue and streaming
Stabilization of distribution lines
Pre-setting the streaming software
Ensuring a recording environment
Here we will take a closer look at each measure.
At LIFE.14 Co., Ltd., we also assist with adjusting pre-check items to ensure they meet the site conditions.
If you have any concerns about the sound or other equipment required on the day of the event, please feel free to contact us.
Thorough equipment inspection
Before entering the venue and before streaming, we check that all equipment is working properly.
The guidelines of the Japan Stage Technology Safety Association require daily checks of power supply and grounding, cable continuity, wired/wireless microphone operation, and permanent speaker and recording/playback equipment, and any abnormalities must be recorded and repairs arranged.
4｜Implementation of safety and health activities
To ensure safety at performance production sites, production companies and facility managers must implement safety and health activities in accordance with Chapter 2: Safety and Health Management in Theaters and Other Production Spaces (p. 031). As a basic requirement, operators in each department must thoroughly implement the following activities in particular.
①Pre-work meeting
Before starting work each day, employers must hold a meeting with workers at their work site to discuss the work content, anticipated hazards during work, and countermeasures. In addition, as necessary, meetings and coordination regarding the day's work safety must be held among the general safety and health manager, safety and health administrators, safety and health managers of each department, and other necessary personnel.
Source: Japan Stage Technology Safety Association " Guidelines for the Operation and Safety of Theaters and Other Production Spaces: For All People Involved in Performances "
For wireless devices, prepare spare batteries and cables, and make sure the transmitter and antenna are working properly.
Regular inspections also require measurements by a specialist, and it is recommended that checks be carried out twice a year to check the output and distortion rate of mixers, power amplifiers, and speakers, as well as for broken cables.
Unification of volume standards
If there is inconsistency in the input levels of microphones or instruments, it will be difficult to adjust them, and this can result in distortion and noise.
It's a good idea to keep channel TRIM and master levels within appropriate ranges, and to decide on standard levels for each speaker before the event.
Additionally, the World Health Organization's (WHO) "Safe Listening Environment" standards recommend that the average sound pressure in entertainment venues be kept below 100 dBLAeq for 15 minutes, that venues measure sound pressure and design facilities, and that earplugs be provided.
1. Limiting sound levels
A maximum limit of100dB LAeq 15 minutes*is imposed, keepingsound safe and enjoyable for the audience.
Source: WHO " Global standard for safe listening venues and events "
To protect the hearing of visitors and staff, set standards and ensure appropriate volume management.
Sharing signal path diagrams
It is important to create a signal path diagram or line chart that illustrates which sounds flow where and share it with all personnel.
By checking the signal input and output directions in advance and checking that sound is actually coming out of each speaker, you can prevent wiring errors and incorrect output.
With a route diagram, you can quickly identify the cause when switching equipment or when a problem occurs.
When streaming, the venue sound and the streaming sound are often sent on separate systems, making it easier to see which routes are affected.
Conducting rehearsals
Rehearsals that replicate actual movements and speaking styles are essential.
The number and type of microphones to use must be decided based on the movement patterns of the moderator and presenters, and the positions where the winners will stand on the stage and the timing of the background music fading must be tested in advance.
By performing microphone checks not only in a stationary state but also while simulating actual movement, you can identify problems such as feedback, volume fluctuations, and poor reception in advance.
During rehearsals, we also check the video stream to confirm delays and volume balance.
If participants will be connecting from multiple locations, be sure to test the connection at each location to ensure stability.
Establishment of a monitoring system
We will have someone in charge of constantly monitoring the audio with headphones during the performance, so that we can immediately identify any abnormalities.
By assigning roles such as stage director, sound, lighting, liaison, and usher, and clearly dividing up responsibilities, it becomes easier to respond when problems arise.
By having this system in place, monitoring personnel can constantly check peak indicators and level meters, allowing them to detect and respond to unexpected volume fluctuations and noise early on.
In addition, having backup staff will enable quicker response in the event of an emergency.
Separate design for venue and streaming
The sound that is easy to hear at the venue is different from the sound that is easy to hear when streaming online.
It is important to deliver even sound pressure to the entire audience in a venue, so the placement and orientation of the speakers must be determined appropriately.
It is important to position the speakers so that the sound reaches the back of the venue, while maintaining a balance so that the sound does not reach too far from the front.
For streaming, a separate mix will be created from the venue, providing clear sound that eliminates echoes from the venue and the voices of the audience.
By splitting the audio into two systems, optimal adjustments can be made for both the venue and the distribution.
Stabilization of distribution lines
When streaming online, the stability of communication determines the quality of the sound.
The main causes of delays and interruptions are unstable internet connections, wireless LAN interference, and insufficient device performance.
Effective solutions include adjusting the bit rate, switching to a wired LAN, and closing unnecessary apps to reduce the load on your device.
Before broadcasting, measure your internet speed and ensure you have the minimum required bandwidth. Also, prepare a backup such as a mobile line or another line in case of line problems.
Pre-setting the streaming software
The streaming software has automatic volume adjustment and noise suppression functions.
However, if these functions are used excessively, the volume may change suddenly.
Therefore, be sure to check the software settings in advance and set appropriate compression/limiter and audio delay settings.
In this case, be sure to check the settings before going live, as updates and restarts may reset the settings.
Additionally, when streaming simultaneously to multiple platforms, we understand the specifications of each and adjust the volume levels and codecs accordingly.
Ensuring a recording environment
In case the broadcast is interrupted, we will simultaneously record the footage so that it can be viewed later.
In addition to setting up recording functions on recording equipment and distribution software at the venue, there is also the option of recording on a separate system to increase safety.
By recording on multiple systems, you can ensure that you can still get the footage even if a problem occurs with one of them.
The recording files will be checked promptly after the event, edited as necessary, and provided to relevant parties.
The advantage of keeping a recording is that it allows you to follow up with participants who were unable to watch the live event due to audio problems.
To prevent acoustic problems, it is essential to plan everything in advance and respond quickly to any unexpected issues!
Acoustic problems occur due to multiple factors, not just improper equipment or settings, but also signal path design, surrounding environment, operational system, distribution lines and software settings, and recording backups.
And even if well-designed, events are live events.
Unforeseen problems may occur.
Therefore, it is important not only to carefully plan the overall event in advance, but also to create a monitoring system on the day that will allow for rapid response to any unexpected acoustic problems that may arise on site.
The optimal solution for event acoustics and streaming audio varies depending on the venue conditions and operational system.
At LIFE.14, we handle everything from designing the video, audio, and streaming to running the event on the day, and we will create the optimal proceedings system based on the event conditions and objectives.
Our strength is our ability to provide one-stop technical design tailored to the venue environment and operational structure, as well as technical support on the day, based on our past on-site experience.
We provide comprehensive support for all technical aspects of your event, from taking preventative measures against various risks such as audio problems, to operational support on the day, and archiving the event after it has ended.
If you have any concerns about running an event, please feel free to contact LIFE.14.
Comments